I had a brief Twitter conversation with Anand Shimpi of Anandtech about this, and he was as perplexed as I was. Nobody could explain the technical basis for this vast difference in idle power management on the same hardware. None of the PC vendors he spoke to could justify it, or produce a Windows box that managed similar battery life to OS X. And that battery life gap is worse today - even when using Microsoft's own hardware, designed in Microsoft's labs, running Microsoft's latest operating system released this week. Microsoft can no longer hand wave this vast difference away based on vague references to "poorly optimized third party drivers".

The new Surface Pro 2 gets 6.6 hours of web browsing battery life. The MacBook Air 11", which has more or less the same hardware and battery, gets more than 11 hours.

I have a Surface RT - the first generation - and as such, I know why. Windows 8 might have Metro running on top of it hiding a lot of it, but Windows 8.x carries just as much baggage, cruft, and outdated shit with it as previous versions of Windows have. Windows 8/8.1 - and Metro in particular - simply suck. Slow, clunky, jarring, cumbersome, battery-sucking, restricted, and limited, with a crappy selection of rush-job, rarely updated applications. You know how resizing windows on Windows 7 or OS X is all nice and fluid? Why, then, is it a slow and jittery operation that brings Windows 8 Metro to its knees?

It's simple: just like battery life, it's a symptom of Microsoft's Windows team not having the balls to truly go for a clean break, as the Windows Phone team have done. And lo and behold, Windows Phone - even WP8, which runs on the same NT kernel - has none of the slowness and crappiness issues that continue to plague Windows 8 Metro (although WP has its own set of issues unrelated to these).

If you want a smooth, modern laptop today - get a MacBook. If you want a smooth and modern tablet, get the Nexus 7 or an iPad. Microsoft still has nothing to show for itself in these areas.

Perhaps you did not bother to finish read the whole article but here we go:

Perhaps most damning of all, if you take the latest and greatest 13" MacBook Air, and install Windows 8 on it, guess what happens to battery life?

One of the best things about the standard 2013 MacBook Air 13" is that it has record-breaking battery life of 14 hrs 25 min (with the screen brightness at 100 cd/m², headphones plugged in and the Wi-Fi, Bluetooth and keyboard backlighting turned off). Under Windows 8 the results are more mixed [..] in the same conditions it lasts only 7 hrs 40 min. That's still very high—it's better than the Asus Zenbook Prime UX31A's 6 hours and the Samsung Series 7 Ultra's 5 hours—but it's only half the astronomical 14 hours + that the 13" MacBook Air is capable of.

Instead of the 26% less battery life in Windows that Anand measured in 2009, we're now seeing 50% less battery life. This is an enormous gap between Windows and OS X in what is arguably the most common form of computer usage today, basic WiFi web browsing. That's shameful. Embarrassing, even.

What do you think now? Perhaps, Windows do not explore some Apple's software/hardware features? That is kind of possible as the system is not really put on any "stress" condition and as so it is quite possible to save a watt here and there.